A Journey

Computers

The feeling that B.Tech. is almost over forces me to feel a bit nervous. I spend (I am not sure whether to call it wastage) a lot of time socializing (at coffee shop and in BC with friends) and rest of the time I am sitting in front of my computer screen trying to develop or explore something. My life at IIIT has been influenced by a lot of factors from Dr. Kamal‘s use of a tablet pc and wifi to connect to the projector for a lecture or Dr. Sangal‘s outstanding way of teaching or the limited bandwidth forcing me to think of alternatives or Nirnimesh‘s inclination towards Linux or Ranta‘s entrepreneurial skills or Sandeep Saini‘s dedication towards downloading. You have so many people around you with exceptional skills in their fields. All these have forced me rethink about myself in one or the other way.

Today there was a mail on squid development mailing list with a link to this page. I was pissed off by the C++ code on the page. At one time I was very good at C/C++ but python killed the interest and knowledge over time. I was strongly inclined towards OOP back then. When I saw the above page today, I felt an inclination towards C++ yet another time. Well, thats me. Just think about something and start doing it without thinking what would be the result. I picked up “The C++ Programming Language” by “Bjarne Stroustrup” from the cupboard and started turning pages. While doing that the page after the Introduction caught my attention. There was a long quote. I generally don’t read stuff like this but I felt some urge to read it. It was

… and you, Marcus, have given me many things; now I shall give you this good advice. Be many people. Give up the game of being always Marcus Cocoza. You have worried too much about Marcus Cocoza, so that you have been really his slave and prisoner. You have not done anything without first considering how it would affect Marcus Cocoza’s happiness and prestige. You were always much afraid that Marcus might do a stupid thing, or be bored. What would it really have mattered? All over the world people are doing stupid things… I should like you to be easy, your little heart to be light again. You must from now, be more than one, many people, as many as you can think of…

New year special proxy server has been created for all users as gift from
IIIT Server Room staff. There are no moderations done on that proxy so all
websites are accessible. Even better there is no connection limit per IP
or per user on the new proxy.

Proxy is accessible at IP _SNIP_ on port _SNIP_. Please feel free to
download as much as you want from this new proxy server.

After failing few (will be disclosed later) written tests in a row, I got a call for an interview. I was pretty surprised as I never expected it to happen. Initially I was nervous because I don’t know c/c++/data structures/algorithms. All I know is Python, Computer Networks, a few Open Source technologies and how to use them to generate cash. Well, after waiting for four hours, I got a chance to meet the interviewers (two). I was nervous as it was my first interview. They asked me for the resume. Below is the conversation.

K : (I never expected this as its the most difficult question of all.) I am a simple guy interested in open source (Throwing random sentences). I believe in on the spot implementing/coding my ideas. Whenever I get a new idea I just code it without spending too much time on thinking about it.

A : What if you face some problem with your idea later?

K : (Suddenly Shiben’s this post popped up in my mind.) I try to fix it and if it doesn’t work in few tries, I just throw the code and recode it (Thanks Shiben for writing that wonderful post).

A : So you don’t do any research before implementing the idea. Do you like research?

K : Not really. A bit. (Lying) I don’t like research. It means a lot of time.

A : So, you participated in Google Summer of Code. What is this?

K : Its a Google funded project in which Google invites applications from several open source organizations and select almost 120+ organizations. Then candidates from all over the world proposes their ideas or picks up projects from organizations’ ideas.

B : You proposed your own idea?

K : Yes.

A : What was it?

K : IntelligentMirror. An intelligent caching system which caches RPM/DEB packages from several mirrors on the basis of package name and not the domain name or protocol. Its a squid plugin.

A : Tell us about this Intranet Chat Service (another project).

K : (Told everything I knew about it).

B : Tell us something about squid.

K : Squid is an open source proxy server used to hide thousands of machines behind a single public IP or to control what users browse in a shared network environment.

A : What is public IP?

K : (Answered)

B : What is difference between public and private IP?

K : (WTF?? I am not a kid. Answered.)

A : How do you hide a thousands of machine behind a single public IP?

K : NATing.

B : (Thinking that I just know fancy terms) What is NATing?

K : (Requesting a paper) Explained every single packet level details of NATing by drawing nice diagrams. (Interviewer tried to confuse at several stages but in vain).

A : (Feeling helpless, whispers to B) Lets ask standard questions 😉

K : (WTF??? Feeling doomed 😛 )

B : What is polymorphism?

K : (Abusing the interviewer at heart) It is some fu**ed up idea using which we can do few things which often confuse me and sometimes confuse the even compiler.

A : (Passing a sheet of paper to me) Write an example of polymorphism?

K : Wrote a function
int function(float a);
int function(char a);

B : Can I change return type of second declaration?

K : (Feeling awesomely confident 😀 ) No.

A : If I change char to double in second function will there be a compiler error?

K : To reference the member variable of current instance of the class.

A : You never declared it. How can you use it?

K : Its provided by C++. You know I used char, int also. (Dumb ass!!)

A : Ok. (Looking at my resume) You have interest in blogging.

K : (Feeling a bit relaxed) YES!!! I have three blogs. One technical, one about life and I bought a digikam a few months back and started a photoblog as well.

B : (Laughing) Interesting!!!

A : Why do you have some many blogs?

K : Because I love buying domains. Then I need to put up something on those domains. So, I write blogs 🙂

B : How many domains do you have?

K : Around 15.

A : Where do you host these??

K : I have my own VPS hosted in US.

B : How much does it cost?

K : $50/month.

A & B : (Looking at me as if I kicked them in balls) WTF!!!! Where do you get all this money???????????

K : [snip] secret 😀

A : Thank you. I think we have asked enough questions.

K : Thank you!

I left the room. After that I returned to OBH (Hostel). I was not hoping that they’ll call me again for another interview. But I did wait for the call till 9:30PM. After that I went to bed. I was about to fell asleep that Kapil Bajaj called and asked me to report in Main Building. I was sure that this will be either a light round in case they are sure to count me in or it’ll be a revenge round in which they’ll ask questions about things I don’t know.

I entered the room and the interviewers were different this time. A bit more nervous then the last time.

C : Interviewer 3

D : Interviewer 4

I grabbed the chair. C picked up a sheet of paper and started writing on it as if he is a BIG BOSS.

C : (Writing an expression on the paper) Remove the extra brackets from the expression.

K : (Understanding that its a revenge. You employ people for software development or removing the brackets from an expression????) Having no clue of the solution to the problem tried writing something on the paper. (An image of “Ajay Somani” teaching removing redundant braces from an expression flashes in my mind. And I was like WOW!!). I gave the solution (I know there are two terms infix and postfix, but don’t have a clue about which one is infix :P) that we’ll start putting things in a stack and will throw away the opening and closing braces which doesn’t have a symbol or character in between them. And will pop them out to get an expression without extra braces. (What a guess?? 😀 and it worked).

D : Can you optimize it?

K : (baah!! I somehow managed to do it. Now what???) Having no clue about optimizing the above, I started throwing some random ideas. Devised one idea and showed to C but he caught it and proved me wrong. Took some more time and devised one more funny idea.
Expression : (((P+Q))*R)Solution : We have two variable i and j with I pointing to first element and j pointing to last element. We enter a loop and start decreasing j and increasing i. When we see opening braces at expr[i] and expr[j], we throw them. And when there is no braces at either expr[i] or expr[j] or both we continue and jump over symbol and characters. While I explained the idea, it somehow worked for the expression. I badly confused the interviewer with my invention 😛 He was like WTF!!! How can this piece of crap work?? I was about to laugh. I enjoyed the moment. It was one of the best moments of the day. He spent almost 2-3 minutes figuring out my newly invented algorithm and finally managed to prove it wrong.

C : (Writing two numbers on the paper) This number ( character array 4568123) is rotated around some number and the original number is (character array 1234568). How would you get the original number from the rotated one?

K : (Having no clue about the domain of the problem) Thinking of swapping numbers here and there. Tried every possible combination but nothing seemed to work. What happened to my pool of ideas 😛 (An image of “Kapil Bajaj” teaching inorder, preorder, postorder traversal flashes in my mind. Kewl!! I don’t have a clue about trees and whatsoever things related to those creatures). Now the big task is to make a tree out of the character array. (While I was telling these to Sachin Goyal. He suggested that plant the first character and water it until it becomes a tree 😀 ) I drew the array in some random orders on the paper and made a tree of some sort with 4 as root and 568 on the left subtree and 123 on the right subtree. (Now, all those organic structures like methane, ethane started crawling in my mind. I somehow remembered the rotation thingy). I rotated the fu**ing thing around 4 and it worked. I felt like the luckiest guy in the world. What a confidence I had at that time. I described the process to the interviewer as if solving tree problems is the easiest of all the problems.

C : What is order of problem?

K : (No clue about the problem itself. How do I know its order? ) Kept quite for sometime and kept myself busy with the problem itself ( I was so happy that I couldn’t get my eyes off the tree structure).

C : (Asking again) What is order of the problem?

K : (Thought about it for sometime) log(n). As the integers are in sorted order. Interviewer looked a bit convinced.

C : (Traping me) How will you make a tree out of that character array?

K : (OMG!! Not again! Tried to explain the impossible.) We’ll take the first character as root. Now we’ll build left subtree. We’ll go on putting the integers in the left subtree as long as they are in same order. In that way the order will break at 8 and after that we’ll start building right subtree (This somehow seemed to work).

C : (Totally frustrated by my guesses which were eventually working) Is this a BST?

K : (The only thing I know about a BST is that it is Binary Search Tree) Yes. (Confident as if I am the one who invented BST 😛 )

C : (Trying to trap me further) Wrote two string “ABCDE” and “CDEAB” and asked to write a function to detect if they are rotated version of each other or not?

K : (Thinking that these are not integers and my awesome ideas are not going to work here 😀 ) We’ll somehow make a tree of a string, then traverse it (Leaving the traversal type for interviewer. I said only traverse it, because I don’t have any idea about how do we traverse a tree in inorder, preorder or postorder. So didn’t want to invite more problems). And then we’ll compare the result.

C : Ok. Thank you. Lets go.

And that was it. My adventurous innovations about trees stopped there 😀

All in all it was total fun being interviewed. I enjoyed every single moment of both the interviews.

This post’s aim is to boast a bit about my plugin videocache and generating some more backlinks for the website 😛 Recently videocache was discussed on a lot of Thai tech forums. They helped me a get a lot of traffic and exposure for the plugin.

Run squid proxy server on your machine in aggressive caching mode by f**cking up with refresh patterns.

Then actually use the above proxy server to browse.

Wasted two hours (5AM – 7AM) in debugging a clean and flawless php script on a remote server with pathetic response time because my firefox+squid messed things up and never requested the actually script from server :((

AFTER HUNTING FOR A CREDIT CARD FOR ALMOST ONE DAY, I GOT A MASTER CARD FROM KIRAN M (UG2K5). BOUGHT THE MASTER CARD ITSELF. WAS TOO FRUSTRATED TO REQUEST FOR THE CARD NUMBER AND PUT HIS MONEY ON RISK. FINALLY REGISTERED FOR A VPS HOSTING ON SLICEHOST.COM FOR A 256 SLICE. I CAN’T EXPRESS MY HAPPINESS. I AM TOTALLY OUT OF WORDZ. MORE LATERZ.

As the time for placements has finally come, I am trying to train myself for the lame questions that companies usually ask instead of asking things related to the real talent.

I am a bit (a bit????) paranoid about pointers, linked lists and stuff that involves pointers. I couldn’t really keep up with the data structures because I learnt to use this WONDERFUL language called python. I was not a bond in C/C++ but my skill level was good enough to write basic codes. Though I didn’t submit all my programming assignments, I used to write C/C++ codes for fun especially during third and fourth semester when I was awesomely obsessed with Object Oriented Programming and classes in c++. But I never used pointers even in that period. After fourth sem, I completely switched to python quitting c/c++ totally. I have been doing fun things like my Google Summer of Code, IntelligentMirror, Youtube Caching and other private stuff in python since almost one and a half year. Python is a real handy language when you want develop projects quickly.

Anyway, I thought I’ll give c/pointers another shot. I picked up EssentialC, Pointers And Memory and LinkedListBasics from Stanford CS Library. Read first two of them from start to end without missing a single word. Read 5-6 pages from Linked List Basics and then thought of coding a very basic linked list with few operations. But unfortunately couldn’t do so even after fighting for one hour. Fifty percent of the time, i was fixing my code because I wrote the damn thing in python style formatting, forgot to declare variables before using them and blah blah… In the meantime Pankaj pinged for the BC session. When I told him the same thing, he said he implemented linked list few days back using arrays … OMG!! pretty easy. huh!! After we returned from canteen, I gave it one more shot. BINGO!!! I did it this time 🙂 I finally wrote some code in C for linked list which finally worked 😀

I was trying to sleep and somebody woke me up. I tried controlling myself, but almost shouted at him. Was retrying to sleep since last one hour, but failed miserably as usual. Woke up. Started browsing the regular sites and happened to check comments on my life blog. And saw a back link. Visited and read this awesome post by Sanrag Sood. I never read such stuff in my life. I am sure the guy is crazy/mad/whatever. Its a must read thing. For me its a post of century kinda thing.